The Roberts family has had a large family garden for several years. Every autumn, after the first frost, they pull up the dead plants and cover the garden rows with black plastic. When it is spring and planting time, they plant seeds though holes they have poked in the plastic. Why do the Roberts use the plastic covering? A. The black plastic keeps the weeds from growing in the bare soil.
B. The black plastic keeps the soil warm so the seeds will grow in the spring.
C. The black plastic helps the organisms that live in the soil survive the winter.
D. The garden space will be covered with grass and animals will graze in the area.

b - the respond is innate and varies over time.

good luck!

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.